Package mode keeps spacing checks on and catches missing subpaths #205

When a design-system package declares the config, its token files replace the app's own stylesheets. A Tailwind v4 package usually ships a theme partial that does not import Tailwind, so the app gets no spacing tokens, no-hardcoded-spacing turns off without a word, and the radius scale shrinks. In a workspace, a component imported from a subpath the package does not export (@acme/ui/fancy) is let through with advice to add the missing files, instead of being reported.

The plan: when the config comes from a package, also read Tailwind's default spacing and radius from the app's own stylesheet; report no-unknown-component when an import resolves to no file; and add a corpus case for a package that ships a theme partial.

Status: next. It builds on the layered configs in #202.